1. Field of the Invention
The object of the invention is a new pressurized container having a small number of parts: two valves, namely a first valve for the dispensing of the product, and a second valve for the fling of the container, either for refilling the container when its contents have been used up, or for adding an additional active ingredient to the product initially contained in the container. The invention is particularly suitable for the dispensing of cosmetic or dermo-cosmetic products in the form of a liquid, a foam, a gel or a cream.
2. Discussion of the Background
Since the time that pressurized devices, for example of the aerosol type, have been in existence, the need for using a refillable system has made itself felt. The advantages of this type of packaging are manifold. One can in fact envisage having available a container with a relatively large volume containing the product, and a small container that can be easily carried and filled at will and can be taken along for a weekend, for a walk, to the office, to the beach, etc.
Moreover, such a small-sized device can be advantageously used for a precise dosing of the product during each use, and this above all in the pharmacological and dermo-cosmetic fields. However, in spite of this need, such a concept has not seen the light of day, mainly for reasons of cost.
One of the problems relates to the difficulty of making such a small-sized device at a competitive price. Indeed, in the case of products supplied in pressurized containers, while it is easy to prepare packages of small size which allow for the original formula, the economic criterion which the device has to meet is at present not complied with. In fact, a pressurized container, even of a small size, requires a certain number of indispensable elements for its operation, that is to say, a can made of tin or aluminium on whose walls there is deposited a varnish and on whose neck a valve is crimped by means of a valve-carrier cup, as well as a dispensing means connected to the valve.
Now the technology of manufacturing pressurized cans does not make it possible to manufacture cans that are sufficiently small to correspond to the volume of a trial dose, that is to say approximately 3.5 ml to 8 ml. Indeed, the task of metal crimping (crimping the valve-carrier cup onto the container body on the one hand, and around the valve on the other hand) which lies in forcing the metal to take on the desired configuration, in particular to come to grip the valve tightly, is an operation that can only be performed on components of a sufficiently large size. This manufacturing constraint hence governs the size of the valve-carrier cup, and consequently the volume of the can which is necessarily greater than a unit dose.
Moreover, these operations of manufacturing the can are expensive, just as is the incorporation of a valve into the can, which, nevertheless forms one of the indispensable elements for the functioning of the pressurized container.
This problem of cost is even more critical when one is concerned with making such a small-sized device with two valves, namely (i) a first for dispensing the product, and (ii) a second for filling the reservoir, either after its contents have been completely emptied, or with a view to mixing a first product contained in the reservoir with a second product contained in an auxiliary container.
There do certainly exist refillable devices of the aerosol type, formed by a "small" can which is surmounted by a first valve, and at whose bottom a second valve has been added for refilling the can. The aerosol is refillable by means of another aerosol device with a greater volume. The cost of this refillable aerosol is thus simply that of a conventional aerosol, to which there is added the cost of supplying and mounting the second valve, that is to say, a very high cost having regard to the small volume of the can.
In fields other than those of cosmetics there exist examples of this type of association between a small volume refillable device, and an aerosol of a greater volume, intended for the refilling of the small device. This is, in particular, the case with refillable lighters for smoking articles (such as cigarettes).
Nevertheless, such refillable devices are always constituted by a container with a first valve for the dispensing of the product, and by a filling system which is in fact neither more nor less than a second valve.
By way of example, there may be cited DE-B-1 166 225 which describes such a can fitted with two valves, each of the valves comprising a valve body and a separate spring for keeping the valves in the closed position in the absence of an actuation command.
FR-A-1 228 733 describes a refillable aerosol can, wherein the filling or refilling is effected by means of an auxiliary can through the same valve as that used for the dispensing of the product. However, this device requires the push button to be raised before operating the refilling, which can sometimes be difficult and after multiple refilling operations it can make the mounting of the push button on the refillable container fragile.
Similarly, FR-A-2 378 572 describes a method making it possible to draw up and store a predetermined dose of a product inside a detachable head. The two operations are effected simultaneously by (i) the compression of a spring while the head is screwed down onto a reservoir, and (ii) the compression of the dose stored at a sufficient pressure by slackening the head and releasing the same spring, so that after the separation of the head and of the reservoir the head has been made independent and can be used as an aerosol can.
Another problem lies in offering the user of cosmetic products, products blending two active ingredients in a single formula. By way of example, one may cite the whole range of "two in one" products that are available on the market, such as medicated shampoos, nourishing hair products, moisturising cleansing creams, etc. Such a packaging is only possible to the extent that the two active ingredients are compatible with each other and with the carrier. Now, in the present state of the art, it is impossible to formulate certain formulas since the two active ingredients are incompatible with each other. Hence "all in one" systems have been proposed which are most frequently complex and lie in packaging the two active ingredients separately until the time of use, when they will be mixed by the consumer in a more, or less, fast and easy way. This type of packaging is frequently found in the field of colouring oxidizing agents and perms.
The difficulty with such products relates to the fact that, since the active ingredients are not stable when they are mixed, they must be used quickly after mixing, and hence must be either single-dose products, or of a sufficiently small volume to be used in a space of time shorter than the time over which the mixture remains sufficiently active, so as to be used with good efficiency.
EP-A-063 759 and EP-A-217 582 describe systems for mixing two products extemporaneously by means of pressurized devices, the mixing being carried out in a device with two valves: namely one valve for the intake and one valve for the dispensing. Each one of the valves has a cup, a valve body, a valve stem, a joint and a spring. Such a design has the drawback of being expensive because of the number of components used. Moreover, it does not permit the manufacture of single-dose devices or multidose devices of a small volume. A similar system is described in FR-A-1 431 181.